A magnetic tunnel junction comprises a conductive first magnetic electrode comprising magnetic recording material, a conductive second magnetic electrode spaced from the first electrode and comprising magnetic reference material, and a non-magnetic tunnel insulator material between the first and second electrodes. The magnetic reference material of the second electrode comprises a synthetic antiferromagnetic construction comprising two spaced magnetic regions one of which is closer to the tunnel insulator material than is the other. The one magnetic region comprises a polarizer region comprising CoxFeyBz where “x” is from 0 to 90, “y” is from 10 to 90, and “z” is from 10 to 50. The CoxFeyBz is directly against the tunnel insulator. A non-magnetic region comprising an Os-containing material is between the two spaced magnetic regions. The other magnetic region comprises a magnetic Co-containing material. Other embodiments are disclosed.
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1. A magnetic tunnel junction comprising: a conductive first magnetic electrode comprising magnetic recording material; a conductive second magnetic electrode spaced from the first electrode and comprising magnetic reference material; a non-magnetic tunnel insulator material between the first and second electrodes; and the magnetic reference material of the second electrode comprising a synthetic antiferromagnetic construction comprising: two spaced magnetic regions one of which is closer to the tunnel insulator material than is the other, the one magnetic region comprising: a polarizer region comprising Co x Fe y B z where “x” is from 0 to 90, “y” is from 10 to 90, and “z” is from 10 to 50; the Co x Fe y B z being directly against the tunnel insulator; at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c directly against the Co x Fe y B z , where “a” is from 0 to 50, “b” is from 50 to 99, and “c” is from 1 to 50; and magnetic Co g Fe h B i directly against the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c , where “g” is from 0 to 100, “h” is from 0 to 90, and “i” is from 0 to 50, with at least one of “g” and “h” being greater than zero; a non-magnetic region comprising at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material between the two spaced magnetic regions; and the other magnetic region comprising a magnetic Co-containing material directly against the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material.
This magnetic tunnel junction (MTJ) consists of two conductive magnetic electrodes separated by a non-magnetic tunnel insulator. The first electrode uses a magnetic recording material. The second electrode incorporates a synthetic antiferromagnetic (SAF) structure as its magnetic reference material. This SAF structure includes two magnetic regions separated by a non-magnetic region. The region closer to the tunnel insulator includes a polarizer made of Co x Fe y B z (x=0-90, y=10-90, z=10-50) directly against the insulator. A layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c (a=0-50, b=50-99, c=1-50) is directly against the Co x Fe y B z, followed by Co g Fe h B i (g=0-100, h=0-90, i=0-50, at least one of g/h > 0). The non-magnetic region between the two magnetic regions uses Ir, Ru, Rh, or Os-containing material. The other magnetic region uses a Co-containing magnetic material against the Ir/Ru/Rh/Os-containing material.
2. The magnetic tunnel junction of claim 1 comprising at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru directly against the magnetic Co-containing material; the Co-containing material being between a) the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material and b) the at least one of nonmagnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru.
Building upon the MTJ design described previously, non-magnetic Ir, Pt, or Ru material is added directly against the Co-containing material on the second magnetic electrode, placing the Co-containing material between the Ir/Ru/Rh/Os-containing material and the Ir/Pt/Ru material. In summary, the stack includes (from the SAF's "other magnetic region" interface): Ir/Ru/Rh/Os-containing material, Co-containing material, then Ir/Pt/Ru material.
3. The magnetic tunnel junction of claim 2 comprising non-magnetic Ni s Fe t Cr u directly against the at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru, where “s” is from 50 to 100, “t” is from 0 to 30, and “u” is from 0 to 45; the at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru being between the magnetic Co-containing material and the non-magnetic Ni s Fe t Cr u .
Expanding upon the MTJ design including Ir/Pt/Ru (as described previously), a layer of non-magnetic Ni s Fe t Cr u (s=50-100, t=0-30, u=0-45) is deposited directly against the Ir/Pt/Ru layer. This places the Ir/Pt/Ru layer between the Co-containing magnetic material and the Ni s Fe t Cr u layer. The layer stack (from the SAF's "other magnetic region" interface) now includes: Ir/Ru/Rh/Os-containing material, Co-containing material, Ir/Pt/Ru material, then Ni s Fe t Cr u.
4. The magnetic tunnel junction of claim 1 wherein the first magnetic electrode comprises dielectric material, the magnetic recording material being between the dielectric material and the tunnel insulator, the first magnetic electrode comprising non-magnetic conductive material, the dielectric material being between the non-magnetic conductive material and the magnetic recording material, the first magnetic electrode being devoid of any magnetic polarizer region between the dielectric material and the non-magnetic conductive material.
In this MTJ design, the first magnetic electrode includes a layer of dielectric material. The magnetic recording material sits between this dielectric layer and the tunnel insulator. The first magnetic electrode includes a non-magnetic conductive material. The dielectric material is positioned between the non-magnetic conductive material and the magnetic recording material. Crucially, the design omits any magnetic polarizer region between the dielectric and non-magnetic conductive material in the first electrode.
5. The magnetic tunnel junction of claim 4 wherein the dielectric material and the tunnel insulator are the same composition.
This MTJ variation builds on the design where the first magnetic electrode includes a dielectric layer between the magnetic recording material and the non-magnetic conductive material. In this specific case, the dielectric material in the first electrode and the tunnel insulator material between the two electrodes share the same chemical composition.
6. The magnetic tunnel junction of claim 5 wherein the composition is MgO.
In the MTJ where the first magnetic electrode has a dielectric material and the dielectric material and the tunnel insulator have the same composition, that shared composition is MgO (Magnesium Oxide).
7. The magnetic tunnel junction of claim 4 wherein the dielectric material has a smaller thickness than that of the tunnel insulator.
This MTJ design includes a dielectric layer in the first magnetic electrode and a tunnel insulator between the two electrodes. Here, the dielectric layer within the first magnetic electrode has a smaller thickness than the tunnel insulator layer separating the two electrodes.
8. The magnetic tunnel junction of claim 1 wherein “x” is zero.
Within the described MTJ, recall the polarizer region with composition Co x Fe y B z (x=0-90, y=10-90, z=10-50). In this variation, the value of "x" in the Co x Fe y B z composition is zero, making the polarizer region composition Fe y B z (y=10-90, z=10-50).
9. The magnetic tunnel junction of claim 1 wherein “x” is greater than zero.
Within the MTJ having a polarizer region with composition Co x Fe y B z (x=0-90, y=10-90, z=10-50), the value of "x" is greater than zero, meaning the polarizer contains some amount of Cobalt.
10. The magnetic tunnel junction of claim 1 wherein the “a” is zero and the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises at least one of Fe b W c , Fe b Mo c , and Fe b Ta c .
In the MTJ design, there's a layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c (a=0-50, b=50-99, c=1-50) directly against the Co x Fe y B z polarizer. In this case, "a" equals zero, so only Fe b W c , Fe b Mo c , or Fe b Ta c are used as the layer in contact with the polarizer.
11. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises at least one of Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c where “a” is greater than zero.
In the MTJ structure which has a region consisting of at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c (a=0-50, b=50-99, c=1-50), where the region comprises at least one of Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c , the value of "a" is greater than zero.
12. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises elemental W.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer consists of elemental Tungsten (W).
13. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises elemental Mo.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer consists of elemental Molybdenum (Mo).
14. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises elemental Fe.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer consists of elemental Iron (Fe).
15. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises Co a Fe b W c where “a” is greater than zero.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer is composed of Co a Fe b W c , where "a" is greater than zero (meaning some amount of Cobalt is present).
16. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises Co a Fe b Mo c where “a” is greater than zero.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer is composed of Co a Fe b Mo c , where "a" is greater than zero (meaning some amount of Cobalt is present).
17. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises Co a Fe b Ta c where “a” is greater than zero.
Within the MTJ with the layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer, the layer is composed of Co a Fe b Ta c , where "a" is greater than zero (meaning some amount of Cobalt is present).
18. The magnetic tunnel junction of claim 1 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises a mixture or alloy of at least two of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c .
In this MTJ design, there's a layer of W, Mo, Fe, Co a Fe b W c , Co a Fe b Mo c , or Co a Fe b Ta c directly against the Co x Fe y B z polarizer. This layer is a mixture or alloy containing at least two of the listed elements/compounds.
19. The magnetic tunnel junction of claim 18 wherein the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c comprises a mixture or alloy of at least three of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c .
In the MTJ structure that includes an alloy or mixture of at least two of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c , the alloy or mixture contains at least *three* of these components.
20. The magnetic tunnel junction of claim 1 wherein the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material comprises a mixture or alloy of at least two of elemental Ir, elemental Ru, elemental Rh, and elemental Os.
In the MTJ, the non-magnetic region between the two spaced magnetic regions comprises at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material. This material consists of a mixture or alloy of at least two of the elemental forms: Ir, Ru, Rh, and Os.
21. The magnetic tunnel junction of claim 20 wherein the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material comprises a mixture or alloy of at least three of elemental Ir, elemental Ru, elemental Rh, and elemental Os.
In the MTJ, the non-magnetic region between the two spaced magnetic regions consists of an alloy or mixture containing at least *three* of the following elements: elemental Ir, elemental Ru, elemental Rh, and elemental Os.
22. A magnetic tunnel junction comprising: a conductive first magnetic electrode comprising magnetic recording material comprising 3 Angstroms thick Fe directly against an alloy comprising Co, Fe, and B that is 10 Angstroms thick; a conductive second magnetic electrode spaced from the first electrode and comprising magnetic reference material; a non-magnetic tunnel insulator material between the first and second electrodes; and the first magnetic electrode comprising dielectric material directly against the Fe; the alloy comprising Co, Fe, and B being directly against the tunnel insulator, the first magnetic electrode comprising non-magnetic conductive material directly against the dielectric material, the first magnetic electrode being devoid of any magnetic polarizer region between the dielectric material and the non-magnetic conductive material; the magnetic reference material of the second electrode comprising a synthetic antiferromagnetic construction comprising: two spaced magnetic regions one of which is closer to the tunnel insulator material than is the other, the one magnetic region comprising: a 7 Angstroms thick polarizer region comprising Co x Fe y B z where “x” is from 0 to 90, “y” is from 10 to 90, and “z” is from 10 to 50; the Co x Fe y B z being directly against the tunnel insulator; a 2 Angstroms thick region of at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c directly against the Co x Fe y B z , where “a” is from 0 to 50, “b” is from 50 to 99, and “c” is from 1 to 50; and 7 Angstroms of magnetic Co g Fe h B i directly against the at least one of elemental W, elemental Mo, elemental Fe, Co a Fe b W c , Co a Fe b Mo c , and Co a Fe b Ta c , where “g” is from 0 to 100, “h” is from 0 to 90, and “i” is from 0 to 50 with at least one of “g” and “h” being greater than zero; a 7 Angstroms thick non-magnetic region comprising at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material between the two spaced magnetic regions; the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material being directly against the 7 Angstroms thick magnetic Co g Fe h B i ; and the other magnetic region comprising 14 Angstroms thick elemental Co directly against the at least one of Ir-containing material, Ru-containing material, Rh-containing material, and Os-containing material; at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru directly against the 14 Angstroms thick elemental Co; and non-magnetic Ni s Fe t Cr u directly against the at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru, where “s” is from 50 to 100, “t” is from 0 to 30, and “u” is from 0 to 45; the at least one of non-magnetic elemental Ir, non-magnetic elemental Pt, and non-magnetic elemental Ru being between the magnetic Co-containing material and the non-magnetic Ni s Fe t Cr u .
This specific MTJ has the following features. The first electrode: 3 Angstroms of Fe directly against a 10 Angstrom alloy of Co, Fe, and B. The second electrode contains a magnetic reference material. A tunnel insulator sits between the electrodes. A dielectric material is directly against the Fe layer of the first electrode; the CoFeB alloy is against the tunnel insulator. A non-magnetic conductive material is directly against the dielectric. The first electrode lacks a magnetic polarizer region between the dielectric and non-magnetic conductive material. The second electrode has a SAF structure with two spaced magnetic regions. The region closer to the tunnel insulator includes a 7 Angstrom polarizer of Co x Fe y B z (x=0-90, y=10-90, z=10-50) against the insulator, a 2 Angstrom region of W/Mo/Fe/Co a Fe b W c /Co a Fe b Mo c /Co a Fe b Ta c (a=0-50, b=50-99, c=1-50) against the polarizer, and a 7 Angstrom layer of Co g Fe h B i (g=0-100, h=0-90, i=0-50, at least one of g/h > 0). There's a 7 Angstrom non-magnetic region of Ir/Ru/Rh/Os-containing material. The other magnetic region is 14 Angstroms of elemental Co directly against the Ir/Ru/Rh/Os material, followed by Ir/Pt/Ru material against the Co, and a layer of Ni s Fe t Cr u (s=50-100, t=0-30, u=0-45) against the Ir/Pt/Ru material.
23. The method magnetic tunnel junction of claim 22 wherein the non-magnetic Ni s Fe t Cr u is 30 Angstroms thick.
Building upon the detailed MTJ structure described in the previous claim, the non-magnetic Ni s Fe t Cr u layer (where “s” is from 50 to 100, “t” is from 0 to 30, and “u” is from 0 to 45) has a specific thickness of 30 Angstroms. The MTJ configuration includes the detailed layering including Fe against CoFeB, the SAF, the compositions, the Ir/Pt/Ru and NiFeCr layers.
24. The magnetic tunnel junction of claim 1 wherein the Co-containing material is elemental Co.
In the basic MTJ design, one region of the second electrode's SAF structure is a magnetic Co-containing material against an Ir/Ru/Rh/Os-containing material. In this specific version, that Co-containing material is simply elemental Cobalt (Co).
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May 13, 2016
June 13, 2017
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